As measures taken by mobile communication carriers against insensitivity and expansion of a communication area, a wireless relay system including a master unit to which wireless signals from a base station are relayed and connected via a coaxial cable or an optical fiber, and a remote unit connected to the master unit is known. In such a wireless relay system, elimination of a dead zone and expansion of a communication area are realized by installation of a plurality of remote units which is connected to each other and also functions as wireless relay devices in a closed space where the wireless signals do not reach.
In such a wireless relay system, when any of the remote units serially connected fails, even if another remote unit connected downstream is normal, the wireless relay system cannot communicate with a terminal. Therefore, there is a known technique in which a failed remote unit is bypassed and a remote unit at the downstream of the failed remote unit and a remote unit at the upstream of the failed remote unit or the master unit are connected.
However, there is a problem that, even if failure of the remote unit is a temporary failure, communication cannot be made until the remote unit is repaired by a repair worker because the remote unit is bypassed.
Embodiments of the present invention have been made in view of the above, and an object thereof is to provide a wireless relay system capable of restoring a temporarily failed remote unit to make communication.